That is a mid level amp, "Hi-Fi", not "Top Hi-Fi" and thus not DSP. The current replacement part no. is 65129143127, it's not really all that expensive. The 8611 is also mid level, but years apart. I can't say it'll work, may be worth a try if you can get a full refund.
An amp upgrade is enticing but not without issues. There are 10 speakers to drive, so you would likely need to abandon a pair or two. The OEM speakers have odd impedances that need to be considered. The amp has odd cross over frequencies, not sure the OEM speakers can properly handle a more conventional set up, they probably can. The good news is you don't have to deal with the digital feed from the head unit as you do with DSP.