well that's a pity
I scoured the market for BO pans a while ago, and the two good ones I found both needed bigger spacing than that.
You could phone or email Armitage Shanks, they have a very big range including many designs intended for retrofitting old buildings such as hotels and galleries. Say you want a close-coupled bottom-outlet pan, with wall to soil pipe centre about 100mm. They are not cheap.
Otherwise, you could use a Horizontal Outlet Twyfords E100 Premium Round, with their S-trap connector. You can see it illustrated as an option in the technical drawing which you can download from
www.twyfordbathrooms.com/products/toilets-bidets-urinals/close-coupled-toilets/e100-round-close-coupled-premium-toilet-pan-ho-flushwise/8960/
With the connector it spaces 80mm from the wall (bottom left pic). (you can put a batten behind the cistern to fill the extra 20mm gap), though the rubbery connection will allow a little movement.
The bottom-outlet pan is not the one you want, because it spaces 230mm from the wall (shown in the same pic, top right) so will not fit your bathroom unless you knock the wall down.
The E100 is a very good range. You may find a good price at QS supplies, but double check the parts you order. Or you could ask your plumber to measure up (show him/her this note and print off the tech drawing) and confirm suitability and order from his trade supplier.
The E100 cistern can be adjusted for increased flush, and the dual-button can be unscrewed with your fingers when you want to take the lid off
The Premium Round has a sort of smooth skirt which makes it easier to clean. There is a soft close, easy-off seat available at extra cost. Unlike Square pans you should easily find a replacement seat in future.