Probably, unless you don't have those skills or the time to perfect them.
Bruce, I bought a FilterBOSS already, but won't install it until this summer as the engine's getting pulled and I'm entirely redoing my water tankage and distribution.
My rationale for buying it was based on several things:
1) is the obvious: it provides an impressive pair of filters that, if one is clogged, the other can be selected without stopping the engine.
2) This can come in handy in places where the diesel is not necessarily clean, or should water get into a tank. Keeping the fuel clean and water-free seems, according to the cruising narratives I've read, to cover 90-95% of the diesel trouble out there, with most of the rest falling under "spares" or "failure to do the basics".
3) The FilterBOSS comes with its own pump, providing not only a level of redundancy, but also a method of polishing one's own fuel should rough seas or a bad fuel-up introduce particulate matter or other containments into your supply.
4) I currently have two 50 gallon keel tanks. I am converting a former SS holding tank beneath the engine (of all places) to a 40 gallon daytank which will contain ONLY polished fuel from the FilterBOSS. The logic is that I could have really nasty stuff in the main tanks, but I'll have at least 24-36 hours of straight motoring range to find fuel.
Yes, you could build such a thing, and people do. But while I'm happy to use a flare tool and a compression fitting on my Atomic 4, I simply don't want to do this job going offshore, because it might fail due to my inexperience, and I cannot do such a neat and compact job.