Yep. I have used both gunbroker and gunsinternational with good luck. One of the things about gunbroker is if you look at the individual vendors on gunbroker they have web sites offering many different items that you can see in one place rather than searching through gunbroker. I imagine gunsinternational is the same way. Gunbroker is a bidding site, gunsinternational offers one price. If I don't like to bid I enjoy knowing that I'll get what I want on gunsinternational as soon as I put my offer in.
Here's hoping that the OP realizes that you can't just "buy guns" on line, auction or straight purchase, but have to have them shipped to a local FFL and abide by federal and state laws in order to take possession of your on line purchase.