Need some advice on motors/baskets for custom built subs

[Doorz1009]

So next season, I'm going to be rebuilding my flat-wall into a 4th order and will be adding a significant amount of power (compared to what I have now). Each sub will be taking 3,000-3,500 watts and a team-mate of mine who will be building my subs next season had some recommendations for what to run, he told me that a motor/basket combo with decent enough cooling would be getting an American Bass HD18 basket and motor, which he could get for a decent price. Money is a bit of an issue, not a huge one but I can't go spending bookoo bucks on my subs, my budget for the motors and baskets is somewhere around 300 ish, still a bit of wiggle room either way but that's what I'm shooting for. Any motor recommendations or basket recommendations will be very appreciated, and being that I'm not exactly a whiz with TS Parameters (I know enough to get me by) if you would be able to explain to me in lay-man's terms why you chose the basket/motor you did, it'd be much appreciated!