I know we're not supposed to think this way, but you can put flats on and maybe never have to buy or change strings again. Good for the starving artist. (I started out on flats in 1964, changed to rounds in the 80's because everybody else did, but never did really like the zing. I went back...
With a 4-10, you might be able to get away with a Gallien Krueger MB200 - great little amp, sounds good, very lightweight, compact, and cheap. Seriously! There's a lot more there in that little beast than its size would suggest.
Almost nobody played a Fender Bassman for very long in the 60's due to the weak speakers and low watts. Most bass players gravitated to the Fender Showman/Dual Showman (w/ one or two JBL D140F). Then came the Kustom 200A tuck and rolled with 2-15 JBL's. Standel, more powerful, solid-state...