> Which parameters would be the best to improve the operations mentioned above?

Start from watching your IO queue in perfmon. Your RAID may be not so
good as you'd expect. BTW, what is your RAID level? 1 or 10 is usually
recommended for databases.
Use separate HDDs for temporary space and database space.
Then consider number of data page buffers. Bigger values are better
for selects, lower - for inserts. You must find balance.
Make page size 8 or 16k. 4k is too small for now.
Your query doesn't use sorting, so tuning of temp (sort) memory
parameters may be less useful.

SY, SD.