I usually recommend the Tascam 22-2, 3-motor, 3-head reel-to-reel recorder, which is the little brother of the 32. It's a light and handy 2-track 2-channel to have around. The tapes are inexpensive and are still readily available in many brands.
As long as you're bouncing material to a superior format, then you won't be losing anything. In fact it is a technique used quite often to sweeten the final mix. You can, depending on your type of music, vastly improve the sonic character of your mix by employing such things as tape compression, which isn't really available in any practical sense for narrow track cassette machines.
I always thought the term should be, "Mix Up" because your mastering deck should meet or exceed the quality of your multitrack.
I use a number of tools in my studio for mix down, including the following:
Tascam 22-2 reel-to-reel
Tascam 102 MKII cassette
Sony Super Beta Hi-Fi VCR
Fostex CR300 CD recorder (exact same machine as
HHB CDR-850, built by Pioneer on the PDR-555RW main board)
To summarize, the Tascam 102 MKII or 112 cassette decks will match your 424 sound wise. However, the 22-2 or 32 reel-to-reel will give you superior sound and more tools and options than just a mixdown machine - tape echo, backwards effects, speed effects, sound-on-sound - hours of fun!
