A 350 Olds is a stout engine, strong and beefy. Parts cost a little more. I would go with a set of headers and nice exhaust first, you will rewarded and reminded of the money you spent every time you drive or start the car (plus usually a dual exhaust style transmission crossmember).
Start thinking about suspension stuff to make the car hook, like rear control arms, hop stop bars, etc. A posi unit. Consider upgrading to 28 spline replacement axles for a Turbo Buick 8.5 and a matching 28 spline posi unit for a 93 up Camaro/Firebird. Most, if not all, G-body cars are came from the factory missing the lower half of the body bushings, really inexpensive upgrade it to get a set for a Turbo Regal and install them. If you make the most of what you have now, make it hook up and leave, whenever you upgrade the engine it will just be faster.
Another route would be a simple nitrous plate system. Set it up to run at 125 horse and have all sorts of fun, as long as you follow the installation and tuning instructions.
I would look for an aluminum intake manifold like an Eldelbrock Performer or Performer RPM. I would also start too look for a 403 or 455, this is where some guys get offended or defensive, but, you can score a whole 403 or 455 for what an new intake and carb would cost. All the parts you buy for a 350 will work on a 403, so, once you score an engine, you can build it to match what you want, while driving the 350.
I would look at Mondello and Dick Miller racing, as some aftermarket cams companies are using grinds for other motors on an Olds cam. The tech book Mondello used to offer is worth the $20 for education on Olds the engine.