Sportster shopping; was wondering about parts availability

[M1n1fan]

The title pretty much sums it up. New shopper here. Am considering an ‘06 (or so) Sportster 4TEC 155. Given that this is now an 18+ yrs old boat and i read elsewhere that parts availability might be an issue, is that something that I should be seriously concerned, or is it scarcity of some of the more “odd ball” parts? I’m concerned mostly about engine parts; those seem to be the most likely fails.