Which one of these is the best? I'm planning to play mostly heavy metal... Which one of these is the best and why?

Also, between the two Crates that are in there, the only differences I can see is the different speaker size. Is there any advantage to a bigger speaker? What are they? Thanks for the help in advance.
I am going to say since you obviously arent going to be playing live... The Line 6 is cool... but You were on a good site. read what it has to say and select due to the ratings.
The Roland hands down. It has a better metal tone out of all those amps. I can't say much for the crates though as I haven't played them. But the Roland is the best imho.
PRS Singlecut Trem

Member #2 of the Coheed and Cambria fanclub, PM dementedpuppy to join.
I haven't heard anything about the Roland. I've heard nothing but good things about Crates and that Line 6 seems to be selling really well and has really good ratings. So it's really hard to choose.
Honestly the line 6 spiders are only the top selling item on sites like musiciansfriend (associated with GC of course) because its beginners who see all the "ultra cool features" and low price and forget that its indeed too good to be true. However, i fell for it last year as well, but i really wish i at least spend my money on a roland. Oh and btw, thats also exactly why the MG halfstack is the number 1 selling amp, heh.
The Gearz:

Schecter Omen 6
B-52 At-100 head + 4x12 cab
Yamaha EG303
Digitech Bad Monkey Overdrive