Hi again.
I'm sorry but I've never owned a 700/900, so I have no idea what it should look like.
I'm glad you already have a 25mm bar in the rear. With your current bar, it might overall be somewhat neutral, which is OK. Actually, the European standard, TUV, calls for being slightly understeering under all circumstances (that means that, whatever happens, those of the "general public" will be facing forward instead of backwards :-); but slightly neutral is what enthusiasts usually prefer, also safe in the right hands :-).

Although I've never had a V-8 240, I vaguely recall* from something I read a very long time ago that the proper front bar for a V-8 not only should be stiffer, but also have a "dip" (for lack of a better term) or U-shape in the middle of the center section to accommodate the oil pan of that kind of engine. [* I could be wrong, but since your ultimate goal is a V-8 installation, I'm just suggesting that you confirm this possibility elsewhere before buying your next bar, just in case I'm right.]

re: "...I like my suspension stiff."
Actually, stiff antisway bars don't make your ride stiff, except when you are on an uneven (i.e., left vs right side) road. Normal dips and rises (that are even on both sides) don't involve the bars because they just swivel on their bushings equally; only when the dip or rise is on only one side will the bars work, and then it could be jarring; or also, obviously, when the car is apt to lean or roll in a turn.
To compensate for these stresses (when the bars are doing their job), I (and I also have IPD's bars) have installed three sets of braces: 1) a brace spanning across the two strut towers, 2) a pair of diagonal braces from each tower to the firewall, and 3) longitudinal braces from the subframe (under the engine) to the unibody channels just behind the "cups" (forgot their name) holding the large, rear bushings of the control arms. Together with poly bushings throughout the front, the car steers very nicely, almost like what I imagine a go-kart should feel like (although I honestly never actually drove a go-kart :-).

Have fun.