I'm on record as not thinking much of Guitar Fetish, as they have some business practices of which I disapprove. That being said, some lines of Alpha pots are perfectly acceptable - hell, I have a few in my amp. One word of warning, however - if your guitar has American pots, the Alpha pots are NOT direct replacements physically (they are, electronically) - they are metric sizes, so your old knobs will not fit. Also, if you are getting a pickguard which is sized for American pots, the Alphas will be a bit sloppy in the guard. It's not actually a big deal, but it's a bit annoying, and at least in theory could lead to your pots wearing out quicker (because they are not properly supported - no data on this, but it does make some sense intellectually). (Allparts sells a little stepped washer/bushing to fix this, but don't bother with it). That said, if you are dealing with a Squire or Asian built Strat, the Alpha pots are probably in there already (though they may not have the Alpha name on them).
I have no idea about the switch Guitar Fetish is selling, but at a guess it is a cheaper Asian made part (like the Alpha pots), and the Asian made switches I've seen all suck. The switch I linked to at Allparts, the packaged Fender switches, the switches Ernie Ball and Dimarzio sell, and the switches you can get from WD (NOT the Dirt Cheap switch - the other one) are all the exact same switch from the same manufacturer (Oak-Grigsby, if I remember correctly), and it is a very fine switch. The switch I was recommending against was the one you linked to in your OP. It's a fine switch (also made by Oak-Grigsby), but unless you have a particular need for it, it is more than you need. All you need is a good quality, standard 5-way switch. Hell, you only need half of it, but since you can only buy whole ones...
In both cases, what I linked to were the standard high end parts for a Strat. In both cases, they are exactly what Fender uses on their high end instruments - CTS pots, and the Oak-Grigsby switch. While you are at it, make sure you change the jack, as that is the one thing where you will get the biggest improvement - the jacks used on cheap instruments are total crap, and wear out in about 1/10th the time of a good Switchcraft - don't skimp on this, as the good Switchcraft jack is only about $3.50 retail. (Well, that's what I charge.) Allparts has that too.
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M.K. Gandhi