I get my kits from ebay with the front seal, cheaper than my local bosch dealer.
But I did that seal on my old 85 jetta turbo diesel that I picked up months ago, because it sprung a leak there after my first drive home! I did that seal and then it started coming out of the cold start lever!
So then I pulled the pump off and did as many of the seals as I could without complete teardown because I didn't know any better. Finally I put a new seal on the mainshaft but after I took the old rock hard seal off I noticed major shaft wear

When I went to start the car up fuel spit out all over my timing belt. I already knew I couldn't use the pump like that after reading on the forums but I wasn't expecting that

Anyways maybe its coincidence that mine sprung a leak elsewhere but be prepared?