Hey David,
yes, a spindle is extremely more advantageous than a hand trim router because of the type of motor that a spindle is and because you don’t fear it burns your house down (see also here).
Most people here buy a cheap chinese spindle/VFD kit at a big webshop/marketplace (that once was a online bookstore founded by a guy who thinks he was in space, a web shop that is often in the news because of the way the employees are treated and paid and hindered to found a union), but if you ask me what I can recommend or what I bought, I would say a german spindle, with which there is one manufacturer that also addresses to hobbyists and consumers, which also offers complete kits consisting of e.g. HFS-8022-24-ER20 2.2 kW 24,000 rpm water-cooled spindle (datasheet) (I would recommend to buy the spindle cable manufactured ready-to-use with it), an Omron MX2 2.2 kW VFD and a cooling station, they even have an ebay shop, and regarding the VFD control cabinet, you can make your own or buy one ready-to-use.
They just don’t support it. This is mainly because a spindle/VFD is no out-of-the-box device. If you are a CNC manufacturer for hobbyists, you don’t have the resources to offer support for that. Generally, you need an electrician (an electrical engineer will also do) to wire such a spindle/VFD, however if you are confident to at least acquire the partial knowledge of an electrician needed for this, many people made it and are very happy with it. The forum contains some success reports.
Yes, I know, the information is spread around, yet here is no howto. But if you set a “@Aiph5u” in front of your search term, e.g. like this or this, you can see that I have already tried to give many hints and answer questions 
However in the manuals of good VFDs, there is everything necessary described for wiring and leading you to a first test run (see e.g. Omron MX2 User’s Manual or Hitachi WJ200 Instruction Manual). Unfortunately, as many have found out, the same cannot be said of the manuals of cheap chinese VFDs.