Quick googling gives us: http://planetpixelemporium.com/venus.html - but I don't have time this morning to sift through the results to find a better one. (Besides, you can easiyl do that part yourself.)

And yeah, if your game is hard sci-fi you will need to do some serious thinking on that base. Even if it's a soft sci-fi setting, consider a city on the talles mountains, and even then a well protected one - thick walls, dome shapes to provide pressure resistance, etc.