Can't change the hand guard? well damn, that might be a deal breaker right there. I was probably gonna try to get one eventually, but that's a bit too "Apple" for me
Phat Eagle stated the IUR cannot have it's hand guard changed, an IUR is a different upper or rifle then the Canadian Colt SA15.7 you enquired about. As it stands right now there are probably less then a #100 SA15.7 rifles (and likely a lot less) out of the Special release 30th anniversary edition of #490 that were made available to the civilian public for purchase (CC offered a total of #490 SA 15.7 and #490 SA 20 rifles for sale). Many SA 15.7/SA 20 rifles have already had their front hand guard changed for personal preference which shouldn't prove to be any harder to do then on most other AR's.
These Canadian Colt SA series rifles have never been available before and will never be available again as Colt Canada has stated this publicly. We were all hoping for CC's C8IUR rifles to become available later this year, but I fear this may never happen after the close of CC's public forum here at Gunnutz.
Since these CC SA rifles are so rare I would expect their value to climb as the years pass, which is something you can't say about all AR's particularly ones made in the tens of thousands like some USA Colts are.
To say these Canadian made Colt rifles are similar to the USA Colts would simple be untrue, CC has explained in great detail w/o giving away trade secrets that their are numerous details that separate them in quality from many other AR's the world over and the Colt Canada cold hammer forged barrels (something the USA Colts do not have) are among the very best AR barrels money can buy. They are tested to a cold weather limits like no other as one example and have proven the most reliable AR rifle in tests with other leading AR rifle companies. My understanding is Colt Canada SA rifles have a warranty for life to the original purchaser in Ontario, Canada.
Canadian nostalgia or not there are few AR rifles as capable, reliable or as accurate as a CC SA 15.7 or SA 20 rifle and the IUR uppers currently available are even better as they are free floated among other things to be sure.
A Danial Defense is an excellent value, but their cost has increased significantly of late and are now in the price range of the CC SA rifles, while Stag rifles have a warranty for life I believe and KAC rifles may offer more features (ambidextrous controls...).
One other important point when buying a Canadian made firearm like a CC SA rifle compared to a rifle from a foreign country there is no need for the rifle or needed spare parts to cross any international borders making for warranty/repair to be potentially quicker (as in months faster possibly) in the case it's ever needed.
If you have the means I would suggest a CC SA 20 rifle with a CC IUR 16" upper for a great combo (available through Gunnutz sponsor companies Wolverine, SFRC and others), otherwise the suggestions of Phat Eagle are a good place to start.
Cheers D