pumps (for beckett)... pressure rated vs non, head pressure?

[smokinreefer]

hey folks,

i am planning on using a beckett skimmer and am looking at my options for pumps to drive it...

now, i have heard that a pressure rated pump is the way to go with becketts, but am kind of at a loss...

is gallons per hour/ head pressure values not the same regardless if it came from a pressure rated pump or not?

for example, i will use the T3 and T4 (because i am considering these for their qiuetness)
the T3 is pressure rated and has 800gph @ 3'
the T4 is not pressure rated and is 1225gph @ 3'
my question is, if i had a 3rd pump that was not pressure rated and it also could give 800gph @ 3', would it be performing equally to the T3, or is there a difference because it is pressure rated?

while were on topic, what pumps are you guys using for you beckett skimmers? opinions? i do want to have my skimmer performing to it fullest potential, but i do have a budget as well! also, quietness is a factor too!

here is just a quick run down of some pumps... its kinda hard to compare as the values i have are all at different head pressure, but it gives you an idea of what the pump can do. (if anyone has values for these pumps, or any other alternatives at corresponding head pressures, pls let me know)
t4
$259
149w
1225 gph@ 3'

t3
$259
149w
800 gph@ 3'

mag18
$209.95
145w
1390 gph@ 4'

mak4
$198.50
110w
1000 gph@ 5'

though i am leaning towards a t4, the mag18 does look very enticing... best bang for my buck?? it looks like i'd get a couple hundred more gph out of it over the t4. the mag may be pretty qiuet submerged, but the t4 is practically silent.

ive been thinking about this skimmer stuff, changing my lighting, downgrade tank, upgrade tank , kalk reactor....getting a house, getting a car...my head is about to explode.someone please help me out!!!
sorry just had to vent.

just curious, anyone thinking of buying a 180 within the next year or so? it less than a year old.