Looking for front door lock.

Try eBay. Several sellers sell nothing but door locks. But that's a very thick door...

I have a similar issue and they are very hard to find. I was forced to carve a recess into the door for the outer part. Your best bet is to talk to a locksmith not go to a hardware store. They may be able to provide an extended tongue and screws.

Schlage used to sell extender kits but they are of course for their locks.