Gigabit G4 in a ATX Case some question

I picked up a Gigabit G4 logicboard 400MHz CPU with heatsink for $8 and change to experiment with. I currently have it mounted in a Full Tower Alienware case, the heatsink that came with it is for the Dual G4 cpu card. The case was originally designed for a Prescot P4 has a huge exhaust fan on the aswell as the PSU has two fans one in the back drawing air in and another on the bottom blowing the air into the case. Under Linux when I run the cat cpuinfo command it reports that the idle temps are 25C to 30C ad under load 50C - 55C are these temps ok operating temps? 

I hope this is the right forum for this!

My idea is to hold an all Mac swap meet here in Southern California. Would anyone be interested? By a show of hands how many SoCal Mac people are there, and how many would be interested in attending and/or selling?

When you post please indicate if you intend to sell or just attend. My current plan is for this to happen mid April, but planning (finding a location, etc.) may take a while. If it is really small I could host the event at my business, but I hope it would be bigger than that.

This is also posted on 68kmla.