Recently bought an '87 Formula as my first project car. The shocks all around are pretty shot. What are some good ones that would be decent replacements without spending too much money?

"Decent" and "too much money" are kinda vague.

That's one of those areas where you get, AT BEST, what you pay for, and it's usually somewhere downhill from there. IOW, if you pay the least, you get AT BEST, .... I'll let you fill in the blanks.

Under no circumstances get Gabriel; they are GARBAGE. Probably not even any better than the OE stuff, which was limp and floppy when new, and nothing but dead weight within 10,000 miles.

Monroe is a "decent" stock replacement. Nothing "performance" or anything like that; all they'll do is keep the car from bouncing like a Xler minivan every time you hit a bump.

KYBs are better, and more $$$. They have 2 product lines; one is about a half-step up from Monroe, one is a really minimal entry-level adjustable.

Koni Yellows are top-of-the-line. Tokico also used to have some that were about like that, don't know if they still do. AFAIK the Bilstein for these cars isn't worth what they cost.

By "not too much" I wasn't trying to find a cheap out way, just not looking to buy top end race quality ones. A good, modern performance shock should be a good upgrade. My roommate said he has heard good things about both Bilstein and Koni, but he's a fox body guy and told me to check the forums for better answers.

I replaced my old rear shocks and springs with KYB Monotube "Gas A Just" shocks and 5665 Moog springs and it has given me what I was looking for. I slightly stiff rear with very little bounce.
Here's there site with a lot of info. = http://www.kyb.com/
and the difference between Twin Tube and Monotube= http://www.kyb.com/kyb-tv/the-differ...n-tube-shocks/

So I looked on O'Reilly's (where I will buy most of what I can), and their KYB section has the Excel-G for both the front and the back, as well as the Gas-A-Just. Would I be best just getting the Excel-G for both the front and the back, or will there be that much of an improvement to get the Gas-A-Just for the rear ones?

It depends on you're driving habits and how hard your going to push the car.
The Excel-G are a direct OE replacement and the Gas A Just are an up grade .
Lets just say the Gas A Just do not have the bounce or dive that the Stock replacements have.
The Excel-G are Twin Tube and the Gas A Just are Monotube.
I would watch some of the videos in the KYB link I posted.