I'm going to put mine up for sale, but really don't know the best place to start. What do you think is the lowest hassle method for selling a modded Jeep?

Why not try the forum? I found mine through this site. Generally forum guys tend to take care of there vehicles so I would buy through a forum before looking elsewhere. Good luck.

I'm going to put mine up for sale, but really don't know the best place to start. What do you think is the lowest hassle method for selling a modded Jeep?

As far as mods they dont really mean anything unless the buyer is looking fot them and selling a modded anything is usually a no no as there thinking its been beat to death.
Theres alway a hassel. Its all on the price as everyone wants it for nothing. If i was to sell in the forum i would look up kelly blue book and sell it BETWEEN private party & trade in price as if they go to the dealer they will have to pay what they have into the jeep + there mark up profit. Heres mine for example from kelly blue book with 33000 miles and every option you can get. Now this is CA PRICES. AUCTION prices are even lower.
07 jeep srt-8
retail = 40,245
p/p = 36,645
trade in = 33,125

I would use the Blue or black book as a guide, but would base my price on more by what everyone else is selling theres for or market value. For example I had a 2000 Acura Integra Type R and had it on the market for 20k. Well after a 10 months of having it on the suto trader I sold it for 18k and it had 38,000 miles on it and keep in mid this wa in 2008 when I sold it. At the time that I was selling it the cars were going between 18k to 24k for the car. I had a few guys call and they all wanted to trade me somthing plus cash for it. I even had a dentist try to offer me 14k for it and I told him for that money I would rather keep the car in my garage and let it rot out! So because the car was so rare I stuck it out and sold it for more then what the blue book said. So this is an example where I would not use the blue book value and instead i would use the market value. Only you as the owner have an idea what your jeep is worth. So try the forum first if not Cars dot com or Autotrader.