Well, I think you weren't very specif about your upgrades. Lets see if my supposition is correct.
Running two gfx cards in SLI
Looking at the Core2Duo 4***
Maybe a raid setup
You probably mean a Core 2 Quad system somewhere in the future and you mention that you want a PSU for the nest 4 years. Also you mention SLI and in that time frame but you're not beying specif about which GPUs you want. I will suppose that you're going for high end GPUs eventually like the 8800GTX or GTS and above during those 4 years.
Well, you will want a stable, quality power supply or else you're riskig too much. Unfortunately that doesn't come cheap. The Antec TruePower Trio 650W is excelent but in 4 years and with the upgrades you want and the to-come power-hungry GPUs I think that you will eventually need more power for those 4 years. I recomend a OCZ GameXstream 700w but that will cost you around 140$US. SLI/Crossfire with high-end GPUs for the next 4 years doesn't come cheap and even that PSU is not garanteed. I got myself a OCZ GameXstream 700w for the next 4 years with ONE high-end GPU and a quad core but I won't go SLI/Crossfire...you may find that you will eventually need even more than that.
But if you go for a quad core overclocked with two 8800GTX in SLI and you wont upggrade for the next 4 years than you can go for the OCZ 700w. It will serve you well. The Antec TruePower Trio 650w for two 8800GTX will work too, but the OCZ will garantee stable and eficient power for that setup for the next 4 years.
No problem at all. But notice that two 8800gtx and the Antec 650w may not be the best setup. For that it would be better the OCZ 700w. But if you go for two 8800GTS than you're ok. At least thats what nVidia recomends...
I'm not sure about beying a very good unit. From nVidia site that PSU is not even in list for SLI with Dual GeForce 7900 GTX or Dual GeForce 7800 GTX 512 MB; its only given for weaker configurations. That doesn't mean its not good, but I would prefer the Antec TruePower Trio 650w any day. It doesn't even appear in this list: http://www.xtremesystems.org/forums/showthread.php?t=10... , althoug that may mean nothing. I find it strange to find the Antec TruePower Trio depicted as Tier 3 when I would almost bet its Tier 2, but I'm no specialist. I would still go specifically for the Antec TruePower Trio 650W or OCZ GamerXstream 700w PSUs.
hum....as I said, I'm no specialist, but the same specs doesn't mean that the components have the same quality. The components may be cheaper ones but with the same characteristics, but thats beyond me. With the Antec and specially the OCZ you're safe as the components are of very good quality.
here is a short review/test from tom's a while ago which shows the max +12v@50a so I would shoot for 80% max loading so 40A load would be reasonably stable, anything higher would probably warrant spending more.
Unfortunately budget and sli don't go well together