I have 2 questions to ask:

1. Do i have the old bootrom for the 3GS?

Model: MB715LL
Serial Number: 5K050JES3NP

2. How can i jailbreak my iPhone without it looking like it's jailbroken? What i was thinking of was installing SBSettings and using the hide app feature to hide the apps i install from Cydia and the App Store. But my only question is, can you still find it by searching for it on the far left search?

Thanks!