which subs would be better for my amp?

i am getting a new setup and was wondering what would be the best spl subs to get. i have a cadence dca 1000 pushing about 1000 rms at 1 ohm. it can also go a 1/2 and be around 1500 rms so thats the power im working with. now i have alot of choices and need some help. fist question is that should i get one good 15 or would 2 or 3 cheaper 15s work. EXAMPLE 1 top of the line RE sub. or 2 lower RE subs. second question is what sub is the best ofr spl. heres my narrowed down list. looking at these subs should tell my price range too hopefully

1.JBL w15gti mkll

2. re sx 18"

3. 2!! RE 15se

4. 3!! kicker CVR 15"

5. 2!! kicker CVX 15"

all input welcome and thanks in advance becasue this is gonna be interesting to see everyones 2 cents.