One thing you need to consider is that few consumer machines will be able to handle every format of ¼” tape so you have to pick the one you think you’re most likely to come across.
Most consumer machines and most tapes recorded at home in the 70’s will be quarter-track Stereo. 60’s tapes were often recorded on half-track machines either stereo in one direction only, or mono in two directions. Some machines were mono…
Neon’s TC-377 recommendation is a really good one. It handles the common quarter-track stereo format and does the common 3¾ips and 7½ips speeds as well as the slower 1 ⅞ips speed.
The Technics RS1500 is way more expensive but has switchable heads so you can play both half-track and quarter-track stereo tapes. It does 15 ips speed as well as 3¾ and 7½
This is a useful resource:
http://www.muzines.co.uk/articles/ta...k-formats/4083