The 8361 for greater SPL from a greater distance, but 1-2m is very much within the optimal range of the 8351 so unless you plan to sit farther in the future, I think the 8361 is overkill for your needs. Look at the Genelec speaker guide below and compare it with your room volume and loudness needs. 8361 for higher volume in larger rooms from greater listening distances.Wanted 8361 but can get the 8351 for a good price , at 1-2 meters , will there be a big difference ?
don't plan to add a sub Becaue of cost
These charts are why I love Genelec - they make choosing the right speaker so painless that the journey is almost boring!
(FYI my 8351 are L/C/R from 2m in my home theater set up with 8350 as my SR/SL/RR/RL)