Welcome to the green side Flumpy! We may not have the zombie reanimation of the Necrons, but we still good ard and propa!
Now to the business side of things. The IA 8 list has some minor game legality issues to it, I mention it because I don't know if your planning on friendly games or if you are more of the tourney gamer. Somewhere on Forgeworld they have an update patch of the IA8 rules, but that was written for 6th Edition in mind and even then not in mind of the 7th Edition Ork book that was released last year.
Some would argue that it shouldn't be allowed in anything other than friendly games because of rule changes such as the Killa Kans gaining the Cowardly Grots rule, which frankly handycaps them pretty harshly (at least in my opinion). Other differences such as the major alteration to Mob Rule and the Waaagh special rule morphing into a Warboss activated ability neither of which were in mind when IA8 was written can also cause a stir if your opponent is already used to fighting the new Orks.
All that being said lets get to the list (also since IA 8 was written to be used in conjunction with the 4th Edition Ork Codex, I'm writing under the assumption you're working off of the 4th Edition Ork Codex). Its not a bad start for an Ork list, particularly one for a beginner greenskin. But there are ways to fine tune it.
For starters the KMBs on the Kans. I was a fan of the KMB on vehicles in one of the old editions of the core rules when you couldn't overheat on a vehicle. Seeing how that's no longer the case, and how you can save a couple points I'd switch over to the Rokkits. Sure you loose a point of AP, but there's a minor point savings, which could net you an Attack Squig on either HQ, or even better those 3 Grot Orderlies for the Painboss. Another thing just to ponder, specifically when you move up from the 1000 pt barometer is adding more in the unit, IA8 was the first time you could field a unit of 5 and one of the good things with the 7th Ed codex is 6pack kan units.
As for the Dreads, well Rokkits tend to not be super reliable, in fact I'd say they're probably the least reliable option for a Dread. Its due to the Orky BS and the one gun one shot aspect of the Rokkit Launcha. Play what you want to of course, but in my personal experience you're generally better off with the 4 DCCW pattern, 3 DCCW and a Skorcha, or the two Big Shoota patterns of Deff Dreads.
When it comes to the Spannas, well they're better than 7th Edition Ork Boyz, but that's really just because of rule changes and the more expensive Shootas. A single 20 mob on the table isn't going to last long, especially when you have your Warlord attached to the unit, it just becomes a big target, but the only other ways of getting a KFF to support your Kan line is a Kustom Meka Dread or a Mekboy Junka and both of those have their own difficulties. Its one of those limitations that you really can't do anything about, but have to be mindful of.
The Koptas as DE styled gunboats is of course the way to go. I'd use them in a more Shooty variety than the burny route, but that's me.
The last thing I have to say is the best of luck to you Flumpy! Orks are a very different army then any of the others on the table, but it's great fun. Even better is when you consider that Orks never loose, because if you win ya Win and if they all died well dat doesn't count.