Do I need to get one with a 1/2 shank or can I get most bits in 1/4? I would like to get a Festool OF 1010 EQ but don't now if I can get over the price

all sow do they come with a case?
The Festool OF 1010 EQ only takes bits with shanks up to 8mm, and I believe 1/4", 6mm, and 8mm collets are available. Of those 1/4" shank bits are the only ones that easily available in North America. Festool used to sell 8mm shank bits, and still do, but the number of styles and bit types has been drastically reduced, at least in the USA. There are other sources for 8mm shank bits but most sources are just going to be mail order. Lee Valley is one source, and in Canada they actually have retail locations.
The advantage to the 8mm shank bits is they have about twice the metal in the shank over 1/4" bits, which reduces chatter and vibration. 1/4" will work for lighter cuts and smaller bits.
Unless you just need a very lightweight router for edge trimming or inlay, the Festool OF 1010 EQ is a great router. If you may need to use the router for a lot of heavier cuts you'd be better of with the Festool 1400 router. It can use a number of the same accessories as the 1010, but also takes 1/2" shank bits. It is heavier so it's not as ideal for light cuts, or situations were user fatigue could come into play.