The key to your application is the ring gear ratio. The first through fourth ratios are all similar in all the transaxles so the big difference is the final drive ratio. What you are used to running is the beetle trans which has either a 4:12 or a 3:88 gear. Changing to a bus trans will actually help you if you are running a small displacement engine. A 6 rib nose cone shift is a good choice and it has a 4:56 gear which you will like for racing. The only thing about this trans is it still has a weak reverse gear. If you want to use a bus trans that has a strong reverse, you will need to switch to a side shift 094. Not sure what ring gear ratios came in these. Someone else on here will know.
Keep this in mind....................
No VW transaxle will hold up to racing in stock form. There are some basic things you can do to help them out. Mainshaft bearing thrust plate is a must, steel shift bushing, chromoly gland nut and a super diff are the bare minimum. Adding a torsional input shaft is a great investment! Good quality racing oil cushions the gears from shock. If you want your bus trans to last more than 2 races, you will need to spend a couple dollars on it before you race it.
Roy