it all depends on how much you're looking to spend. remote start is good for those cold mornings, or even just to get it giong a few seconds before you get it... plus i like it just to show off, lol. remote start systems vary on price, i've seen some setups that are 'cheap' and others that are way up there.
before doing this on your own, i'd go around to a few shops and get price quotes, for what youd' pay for a decent remote start system there might be a place that will put it in with the purchase.
i'd go with a good system though, one that'd allow you to lock/unlock/remote start/ aux all in one remote. aka vipir system! go look around though and get some quotes from the stores, they can probably do it quicker and also guarantee their work in case something goes awry.
good luck with it, i hope it goes well