Well you can mount them up front with oem cast manifolds. We have such a setup on a coworkers 57. I would say then you have less overall weight from not having charge piping running from the back of the car and you save weight from no oil scavenge pump.
The weight would be shifted to the rear but a pair of smaller turbos with v-band housings, wastegates, everything comes in at less than 50lbs.
You would save money on mufflers if you don't plan to use them but everything else is a wash. (well, more money on cold side piping with rear mount). Can use stock manifolds with engine bay mounted turbos and both can be used with stock heads and intake manifolds.
If that's what you prefer than by all means do what you like. From a functional standpoint I like close to zero perceptible lag which I've yet to experience with any rear mount setups.
Bed liner undercarriage looks nice btw. Seeing it on more and more cars and it's starting to grow on me.
