<<Regardless, it makes sense to use a bigger filter because you get a little bit more oil circulating throughout your engine.>>
Uh, no. You don't get extra oil circulating through the engine. You do get a tiny bit of extra oil inside the filter itself, but a physically larger oil filter does not increase the amount of oil circulating through the lubrication passages. The oil pump pumps X volume of oil through the system in Y amount of time. In order to increase the amount of oil circulating, you must either increase X (more volume in same time), decrease Y (same volume in less time) or do both (more volume in less time). A larger oil filter (neglecting restriction effects which are certainly small enough to be ignored) has zero effect on X and Y. In fact, the only componant that can alter X and Y (aside from engine speed, which affects all oil pumps and is thus unimportant in this discussion) is the oil pump itself. A physically larger filter has the same effect as a larger sump. It allows more oil to sit around. It does not allow more oil to circulate.
As for the original question, unless you are really beating the crap out of the car, synthetic (full or blend) will not offer any measurable advantage in the next 20 years or so. Regular oil changed at 3,000 miles with a decent (I recommend FRAM) filter will be more than sufficient for any normally driven liquid-cooled street car. Now, if you routinely drive in hot weather, dirty environments, accelerate hard, and basically kick the crap out of the car, then you will achieve some benefit by switching to synthetic. Personally, I run regular oil in my normal car (209,000 miles and counting) but synthetic in my air-cooled cycle and in my air-cooled 914. Synthetic handles thermal extremes better than conventional oil and air-cooled engines tend to heat up a lot more than liquid-cooled engines do. Also, air-cooled engines rely on the oil as a coolant to some extent as well. If you really beat on the car and think you need synthetic, I would use Mobil 1, I've had good luck with it and it seems to be generally considered to be the best synthetic that is widely available. As for conventional oil, they are all fine. I use Texaco/Havoline myself but Castrol, Valvoline, Penzoil, etc are all fine too.
ZV
EDIT: Just to point something out, whatever you do, do NOT use any oil/filter/lubricant that has Teflon (also called PTFE) in it. The claims that Teflon (PTFE) increase lubrication are not only patently flase, but since Teflon (PTFE) is actually a particulate SOLID, it is filtered out by the oil filter. Even if the Teflon (PTFE) is smaller than the filter's pore size, it should be noted that Teflon (PTFE) expands greatly when heated, so once the oil reaches operating temperature the Teflon (PTFE) particles will expand and be filtered out or get stuck in small oil passages. There have been cases in which accumulation of Teflon (PTFE) deposits have severely restricted oil flow in small passages. Again, do NOT use anything with Teflon (PTFE) in it. An example of a product to avoid is Slick 50.
EDIT 2: After reading the oil filter reviews, I think I'll take back my FRAM recommendation and I think I'll be using a Purolator filter next oil change.
EDIT 3: Grammar.