Hiya and welcome, ooh I did giggle when reading he growled & peed on the Vet. Poetic justice for he who was about to stab him with a sharp needle.
My girl Chi Bella was much bigger than your boy and I think right now at 8 or so months she's close to 9lbs. IMO bigger ones are great, they can tear a$$ around with the best of them and you don't have to worry about them being so fragile, she's quite happy play fighting (and beating up) her Boston Terrier & Schnauzer buddies whereas my tinies stay on my lap looking petrified at the proceedings below lol. Only now is my little 3.5lb boy willing to get in an have a go, but it took a while for his confidence to buiild against the other clumsy boofheads.
Oh, and they'll ALL fit in a purse, it's just the size of the purse that matters