syrian armed forces will likely at the end of the war reduce its forces by quite a bit and efforts will be focused on rebuilding the country of course security is still important and they will retain a large reserve forces. They will have a large amount of experience from the war.
As for equipment in the public eye and on paper it will remain looking large but in reality most equipment will be retired. aircraft more so. flying hours will be drastically reduced. and syrian defence budget will be reduced unless Iran gives funding.
ground forces will likely keep whatever is still in reasonable shape. Most aircraft will retired will cannibalising from other aircraft to others flying. air defence will likely remain as is.
As for any form of procurement/donation/token prices etc. It's highly likely it will only come from Russia Iran and Belarus. ground forces will likely operate soviet era equipment for many many years and I'd expect small purchases of overhauled minor upgraded equipment you might even find that syria will only pay for the overhauling minor upgrade and transport of the equipment. As for aircraft it's very unlikely that they will get anything new maybe at a stretch yak-130 & mi-17 & mi-35. you will likely find in a similar deal as I mentioned for ground forces paying for overhaul etc for ex Russian su-24, mig-29 (minor upgrades), su-27, L-39, mi-24, mi-8. air defence is likely the only thing that they will buy new and in very small numbers. of course Russia could sell them older systems such as S-300, tunguska, sa-8, sa-13, and I'd imagine stocks of sa-3, sa-5, sa-6 missiles will continue.
All in all the Syrian forces equipment wise will remain very dated for at least the next 10-15yrs. And your likely to see a greater presence of iranian equipment both obtained from during and after the war. Their greatest assets being experience and and not just regular troops but having an experienced reserve force.
As for China I doubt any military assistance will ever happen. when syria was on its knees China did nothing. anything military with China will only involve a purchase of equipment and syrian won't be buying much for sometime. As long as Russia and Belarus has vehicles in storage syria won't be buying Chinese vehicles. and I highly doubt purchases of Chinese aircraft when Syrian pilots have been flying soviet aircraft for decades and as I stated they will likely only get secondhand aircraft from Russia it also means less training and maintenance training.