GSR doesn't have any bigger brakes then any 94-01 integra (excluding ITR).
It sounds like you weren't pushing on the brake pedal hard enough...
BUT the brakes are a bit "undersized" for a swaped hatch...
That said I'd say you have two options with one being much more "blingy" then the other.
Option #1
1.) 1991 honda civic EX 4 door Master cylinder (this is a 15/16 MC and is THE only direct bolt on to your brake booster) retail is around $150-160.
2.) Get some Hawk HP+ or HP pads, or if you want some thing a little more agressive go for the carbotech bobcat.
3.) purchase some 15x7 wheels (rota slips, 949racing 6UL, ect ect)
4.) purchase some good performance tires you have MANY options (falken azenis, Toyo R1R, Bridgestone RE-11)
Option #2
1.) 94-01 Integra (non ITR) front spindles with hubs/bearings/rotors/calipers, and rear trailing arms with hubs/bearings/rotors/calipers. $300 (used in good condition
2.) 1991 honda civic EX 4 door Master cylinder (this is a 15/16 MC and is THE only direct bolt on to your brake booster) retail is around $150-160.
3.) Get some Hawk HP+ or HP pads, or if you want some thing a little more agressive go for the carbotech bobcat and new rotors at autozone/kragen (cheap ones).$80-120 for pads and $60 for a set of rotors.
4.) purchase some 15x7 wheels (rota slips, 949racing 6UL, ect ect)$400-$600
5.) purchase some good performance tires you have MANY options (falken azenis, Toyo R1R, Bridgestone RE-11) $500 to $700
Option 1 would COMPLETLY solve the "issue" you have with your brakes, and is a fine option.
Option 2 would completly solve the issue, and maybe others in the future. Only issue with this is sometimes the hubs/bearings/calipers are trash and need to be replaced. This can add around $800 to the cost of the brake swap.