Hey there,
Hope you are doing good on your side,
I just read your job description and we are expert with custom work related to vBulletin. We have been offering our services for more than 8 years and we are verified coder and designer on vBulletin.org.
With our extensive experience we are able to perform smooth upgrade from vB3.8 to vB 4.2 and provide you solution for add-ons. As we have developed and upgraded many add-ons for different features.
Please feel free to ask if you got any any questions. We will be glad to assist you with it.
NOTE: This upgrade is major upgrade so final price will be later after complete productive discussion.
Thanks,
vBtise