depends on your budget really.
Anything above 400 and youre golden. Anything under and its pretty difficult.
Basically, go check out any $400 deck that fits your criteria (narrow ww, flexy, somewhere around 148-150), then walk out the shop and log on. Then head to your favourite cheap or used gear site (whiskeymilitia, craigslist, ebay etc) and go buy two decks from a few seasons ago that actually fit what you're both after. With a bit of effort, you shouldnt have too much trouble finding a deck from a couple of seasons ago for under $200.
Honestly, this has all the makings of the boys idea
I reckon you said "i should buy a new deck! im sick of rentals..." and he said "dude, thats a wicked idea, tell you what, i kinda want a softer deck and ive heard womens decks are softer and shorter, so how about if i give you a bit of cash and then you get a deck we can both use!!!"
Probably best you both get your own decks.