I agree, it would be incredibly useful if there were a timely and reliable resource or center for purchasing and getting support of these diy goods (which the forum acts as somewhat of a proxy for, thank you).
I know it's a niche market and it's dealing with relatively complex and specific things, but the level of service and support from so many diy providers is all over the place. It takes something that is not easy and makes it even harder. I'm new still, got into this about a year ago and that's one of my biggest takeaways from it all.
Rather than layout all the inconsistencies and long waits from folks and companies I've bought from in that timeframe, all I can say is in my opinion the most professional and helpful so far have been DIYRE, Hairball, Seventh Circle, Sound Skulptor, Dachman, (all relatively establish companies already) and now soliloqueen's new Arienne Audio.
I'm not at all expecting Amazon level service but having to learn the hard way that you'll in general need to wait 4 weeks of silence and then have to send an email to most suppliers to get a shipment going is not a great experience (and requesting build support outside of the forum is equally fraught). But without other options we're kind of stuck with it as it is.