Bottles--WWYD?

keg

I'm expecting #3 and while my first two (twins) were breastfed some for 9 months, due to a variety of issues, I always had to supplement.  For this one, I hope to EBF.  I will be going back to work so I'll be dealing with bottles in some form or fashion.  I kept a bunch from DDs with the thought of just getting new nipples.  However, I'm wondering if this makes sense or if I should just start from scratch.  This is what I currently have:

--What would be considered the Avent Classic bottles.  However, they are of the vintage that leak horribly if you didn't line up the nipple and collar just right.  I think they were fixing that when DDs were little.  Not sure if new collars were part of this fix.

--Cheap Evenflo and Gerber bottles

Would you get replacement nipples for any of these options or try something new?  Thankfully my girls went back and forth between bottle and breast with no issues and were started on super-basic bottles when they were in the NICU for a few days.  I'm just kind of clueless when it comes to one baby!