When the factory sunroof is stripped it does not weigh much. There are a couple of ways to hold it in place. I have used urethane windshield adhesive to hold it in place and never had issues. Another way is to build brackets to hold it in place. The front is very easy, take your factory front mounts and flip them upside down and install them in factory location. The rear I used a small piece of sheet metal (I think about 14ga) and bent it in a L shape, drilled two holes in the shorter side and screwed it in where the plastic track was in the sunroof. I will try to get some pictures if you need me to.

Couple points.
1) Sunroof.
There are two options 99% of the guys gut the roof panel as much as possible and the bolt it in with mounts. These can be "clean mounts" from the underside or "frankenstein clips" from the outside. Either way the roof if in the car still must be BOLTED in place. Glue will not pass race tech. I have seen a sunroof "glued" in that popped out right during tech. Needless to say the driver was looking our the pits for metal to make "frankenstien clips" shorlty there after. The "clean mounts" are nicer since they are under the roof and hold in, but they take a bit more fab work.

The other option is to reskin the roof using a non-sun rood top. I can be done and is legal, but IMHO alot of work and money for no real purpose. If you want to be fancy use "clean mounts" and bondo in the seal area on top to give it that clean look from the top. Over time chassis flex could cause the bondo to crack though.

2) Motor
Few things... Do you NEED the headgasket? It can happen and older working headgaskets fail when put under racing stress, but if it ok now you may just want to wait. Reason is that if you pull the head you should get the head check for flatness and good valve seating. Restoring the head to factory specs is best way for these motors to make hp. Or at least get back to stock hp levels.

Also even a low mileage motor should get new timing belt and balance shaft belt. These are cheap and like Ken said a failure can be costly. Racing does not put much extra stress on the belts, but is a good idea non the less.

Also ROD BEARINGS. Even on low mileage motors doing rod bearing before you put R-compound tires on the car. The extra grip and RPM can cause issues. You probably can get away with a few days going rather slow with street tires, but once you start pushing old rod bearings can cause a major issue. So pull the pan and change them. Parts are cheap, but the labor takes time. You can do it with the engine in the car and an engine hoist to support the motor.You can also rig up an engine support as well. With the pan out it is a great time to get the pan baffled as extra insurance.

Oh... never track the car on anything less than 15-50 or 20-50. I have heard guys using 40wt, but most of time guys using 30wt oils end up with spun bearings. Not good. Also always check the oil before each run session. These cars can burn oil at high rpm and being below full can cause bearing issues. Never overfull, but always keep it AT FULL. Too full has its own issues as well. Don't worry about this stuff as it really pretty easy once you get in the habit. I have however seen issues resulting from guys not taking these simple precautions. Otherwise the cars are quite solid, but also prepare for a few lingering issues to come up as you would expect fo any 20 year old car getting put through racing duty.

I have been driving this car since October of 2000 and have seen or had happen to me just about everything. Yet I am still here an consider the 944/924S an excellent racing platform.

Yep - it NEEDS a headgasket. Oil was milkshake. I never started the car because it had been sitting for too long with bad fuel but the PO said he did start it before listing it for sale it it blew white smoke out the tailpipe. That plus the milkshake sealed the deal for me.

So I'm going to pull the motor in about a month and do the belts, head, rod bearings, etc. I know the head and belts can be done with the motor in, but I'd rather go through everything on the stand and clean the mess up while I am at it.

I know it sounds rough, but I confirmed all the electrics work before stripping the car. I drained fuel and checked belt tension. Tension was OK even though I cannot confirm how old the belt is, but I chanced it and cranked the engine just to confirm all the electrics worked. Cranked just fine and I am convinced it would have started if it had fuel (lines were disconnected).

I plan on running the car in F Prepared Solo autocross before tracking it. And keeping it street legal to drive to and from the track and for break in. This is to sort the time out and spread my build costs out over a period of time while still having fun with the car.

You will need to fully tear it down and rebuild it. All the main bearings need to be replaced as well as the rods. Plus it will be a long time to clean the internals. My currnet motor had the same milkshake situation and I needed to fully clean it all and even had piston ring stuck in the pistons. My was sitting for a while so that may have hurt it. Once cleaned and with fresh bearings and seals the motor has run great for many years.