Current amps works very very well with fullrangers.. So F1 or F2 would be an excellent match with your spks. The choice of either F1 or F2 would be more of your own personal preference.. If you like the SET type of sound then go for F2, if you like the PP type of bass, punch and control then go for F1.
As an owner of an F1, F2 and Abbey, perhaps I can add some information. With the Abbey, I perfer the F1 over the F2. Does that mean the F1 is better? No, I think it's a better match. The Fostex 166E is a musical speaker with a nice warm character, but it is not as resolving or fast as some of its higher priced relatives. The F1 tends to excel in what the Fostex is lacking, so the combination is .... well fun. With the Fostex's warmth, you will have plenty of tonal color.
The Abbey with F2 is still nice, but much more laided back in presentation. Tonal color is fleshed out a little more, but PRAT is reduced by a corresponding amount. Which is better? Depends on your taste. For me, I like the F1 with Fostex drivers and the F2 with Lowthers. But your taste may vary. Hope this helps.