sound blaster cinema 2 is just a variation of SBX which are audio drivers/software. you do not need specially certified speakers to run on them, anything would work.
as far as your options go for $150 or less?
z506 for about $100. would give you fair quality surround sound. not excellent, but adequate for the price. there are some other brands of pc 5.1 sets which would give a similar quality level.
z523, creature3, soundsticks 3 all run about $150 usually. would give you 2.1 sound only but at better audio quality than the z506. basically a trade giving up surround sound for better audio quality.
getting a pair of budget hifi speakers such as the dayton b652, micca mb42, pioneer bs22 and hooking them up to a cheap amplifier is $70-150 range. you lose out on a subwoofer but gain some nice sounding speakers which will put most pc speaker sets to shame given the price. you can still get decent bass without a sub but will miss out on the lowest of the low tones.
as for headphones and headsets, if you wanted to use SBX's virtual surround sound you would want one which is analog (3.5mm connection(s) not usb). some good options for under $150 would be the hd518/hd558 (neutral sound), ad500x/ad700x (bass light sound). a good mic would be the modmic, maybe the moovmic or a desk mic like the snowball/atr2500. as for headsets, the hyperxcloud is not bad at its price range however the hd518 is better for just a bit more (though the hxc is a headset and includes a mic for that price as well).