>>6676476>>6676498The RD Unicorns are excellent, so they're a great choice provided you aren't looking for a transforming Unicorn toy (the RDs are strictly one-mode only figures). Among the RD Unicorns, you want to make sure to purchase RX-0s that are RD #103 or higher. Bandai made RD Unicorns before that, but #103 is when Bandai introduced the "Full Action" frame that they have since used for all subsequent Unicorn RDs. The Full Action improved upon the older releases by being much larger, better proportioned, and more poseable.
Now, starting from #103 you still have a couple options. If you want a Unicorn in Destroy mode with a red frame, you can either get #103 or #159. The only difference between the two is that #159 has notches in its lower legs that allow you to plug in the grenade racks for the Full Armor load out (note, #159 does NOT include any Full Armor parts, it's just fully compatible with them; all Unicorns post #159 have the same full compatibility). If you have zero intention of ever getting the Full Armor parts, you could just get #103 and not have those notches in the legs (though they're fairly unobtrusive).
If you want Unicorn in Destroy mode with a green frame, all the current options were web exclusives but they didn't just too high in price on the secondary market. The best one (in my opinion) would be the one that included the Shield Funnel parts. One thing to keep in mind; the green frame Destroy mode Unicorn is being re-released in April 2018, will include the shield funnels AND will have additional tampo details, so you may want to wait.
If you want RX-0 in Unicorn mode, the only option using the Full Action frame is going to be #140. This one DOES include the complete Full Armor parts, and unfortunately that makes it a bit pricey on the secondary market. RD #40 (heh, exactly 100 releases older) is the prior Unicorn mode RD, and I've heard it's actually a fairly solid figure, so that may be an alternative to look into.
