Well for YF-19's you've got some choices.
In the 1/72:
Hasegawa YF-19 (plastic kit), the cheapest and most readily available with good quality, fighter only.
Club-M YF-19 (resin), highest detail, difficult to find and will run you upwards of $150.00, also fighter only.
Wonderfest event only kits (resin), there's several battroid only kits in this scale but are rare and very expensive $200+.
There is also a fully variable YF-19 kit put out by SHE (I think) (also resin). It's somewhere between 1/100 scale and 1/72 scale. It's extremely rare and extremely expensive. The big draw to this is it's variable (all 3 modes) but not all that detailed (this is usually the tradeoff)
I'm sure there's more out there but the 1/72 scale is all I know.
Welcome to Macrossworld.