Originally Posted by daverobbo5

at most/many tracks there are two buggy classes.
1.27T is stock=17.5 brushless.
2. Mod/open = whatever you can handle
if you've got a 19T some tracks may ask you to run in the mod class. i'm pretty sure that you'll find that the 19T won't be too competitive with 8.5 or 7.5 turn brushless that some might run in mod class- but then again it might haul.

you might need more like 15T or14T Double to be competitive. as you know, mod can be pretty action packed with some drivers taking in seriously if you hold them up/rub wheels or collide with them but you said your driving skills were good so that might not be a problem.

stock can be a bit more relaxed. a hobbywing or speed passion combo can be had for about $100USD or cheaper if you hunt around. any money you spend on cutting the comm (which would be a good idea) takes away from the brushless you'll eventually want/need. but if you've got the $$.
I ran a 27T in 17.5 4wd stock recently and got smoked by other drivers in speed and punch. 17.5 arrived in post and suddenly i was in the action and enjoying it!
you could grab a new 27T brushed and swap out the 19T if it turns out to be too slow. some tracks might just let you run the 19T in the stock class. it'll be fun anyway. good luck