tranny help conversions?....

i have a 99 cobra 100K miles plus i lost the tranny yesterdy... i need to know where the best place to get either a t-45 or if it would be better to to use a different tranny or if any other mustang trany's are interchangable with my model
 
If you must replace it with another T-45, check e-Bay. i found mine for $300 off of 2000 with 21000 miles on it.

But if you can, instead of replace T-45 with another t-45, consider TKO or T56. you'll be happier in the end