Will any AR quad rail work? Can you suggest one that works so I have a starting point?
Thanks for the responses.
I swapped out my Sport handguards for this one. Easy swap,fits perfect and a reasonable price at around $53. They will fit yours too. The Delta ring is "do-able" by hand to get your old handguard off,helps having an extra pair of hands.

You will call it a couple names getting it pulled down

It helps to find the slit on your old handguards where they meet and "maybe" use your pocket knife to GENTLY split them appart. Who knows how long they have been there,it does help with a GENTLE nudge getting them split appart once the Delta ring has been pulled down. By hand you'll find they come off easiest getting half the Delta ring down and getting one side off at a time,should be top half and bottom half. No need buying a tool you'll only use MAYBE a couple times to get the Delta ring down on it's spring. This quad rail is very well made and I would buy it again.
CAREFUL with front sight if it's mounted on your gas block. It WILL melt plastic/polymer sights. Make sure they are metal.
Mine.
Leapers UTG Model 4/15 Drop In Quad Rail Carbine Length with Rail Covers Black
Made in the US. Four-sided, mil-spec picatinny railed handguard allows for a huge array of accessories and is precision machined for maximum strength.
Two piece design replaces your original plastic handguards and locks in place for a secure fit. Installs easily without gunsmithing or modification to the barrel.
Includes black rubber rail guards for comfort and protection.
Hard anodized aluminum construction for superior wear resistance. Four rails with 14 slots per rail.
Fits carbine length M4 and AR-15 style rifles. BLACK.