Transmission help

[SuperSport]

Hey guys,
I just picked up a 68 Nova and it happens to be the first manual trans car I have ever owned. It has a 3 speed with column shift and I must admit it is pretty fun to drive. The first order of business is getting the the shifter to the floor but, before I invest in a $200 shifter from Hurst I was wondering if I should move on to a 4 or 5 speed upgrade and then buy the appropriate shifter. The goal would be to upgrade but keep costs low as the car requires attention in other areas. Sadly, I am not one of the millionaires on Lateral G (lol). So, a budget upgrade is what I am inquiring about. Hopefully keeping the stock clutch, bell housing, and drive shaft to keep costs down. Do I have any options or should the functioning 3 speed stay?
I have absolutely no knowledge of manual transmission options so help would be greatly appreciated.
Thanks, SS.