To answer your question about needing it more as time goes on, I think that you are right. With rigid enough water change schedule, you can maintain it pretty will "skimmerless", but in general nutrient/waste buildup is slow over time. Before the days of protein skimming/live rock systems, "Old Tank Syndrome" was fairly common... tanks would motor along fine for a year or two and then crash.
There are some people who pride themselves in not using a skimmer, but personally I would not consider even for a moment going without one... and I will never again try to get by with a mediocre one either.
As for models, among HOB skimmers the AquaC Remora, as SuperClown suggested, is pretty highly regarded. I'd also look into the Reef Octopus HOB model. I don't know anyone who uses that particular one, but Reef Octopus skimmers as a whole are known as one of the best skimmers that doesn't cost an arm and a leg.
If you end up with an in-sump skimmer, any of several Octopus models would be nice. After recently switching to an SWC skimmer on one of my tanks, I am comfortable recommending them also. The Xtreme 120 Cone skimmer would work very well for you if you have the room, and it is less than $200. I bought a 160 cone for my 90g tank, and it is doing a great job (plus it is almost silent).
HTH!