Sounds like a solid plan. I'd recommend picking a domain other than War if you're going into Ordained Champion, since you can get War as a bonus domain from that PrC -- however, it's ultimately up to you. You get a bit more flexibility in spell selection if you take something else besides War, since you wind up with three different domains to pick spells from, but on the other hand to accomplish that without a net loss of available feats requires you to trade in your granted domain powers to make up for the feat slots spent on weapon proficiency + focus. If you'd prefer to keep the Spell Focus (Enchantment) granted from the Domination domain, then War is a fine choice.
As far as the armor goes, most of that can generally be handled outside of the rules as a simple matter of description. Armor spikes are a relatively inexpensive add-on for a suit of armor, and while you may not be able to use them to attack without getting the martial weapon proficiency that doesn't mean you can't still get them just to look cool. The simplest way to do the gauntlets would be as spiked gauntlets; there might be actual clawed gauntlets in some supplement or another, but odds are they're exotic weapons and considering it's mainly a matter of flavor and description the standard spiked gauntlet should do just fine. You could probably also pay the price for a masterwork tool to make your armor considered a "tool" granting a +2 circumstance bonus to Intimidate checks because of how scary it looks. Make sure to run this by your DM first, though, since it's not strictly speaking something that's actually offered within the rules. It would be a pretty reasonable thing to allow, though.
If you want to add magic to contribute to your armor's scariness, you can look into the Fearsome property from the Magic Item Compendium. Making your armor Fearsome costs 15000 gp (not a +1 bonus!) and lets you panic all creatures within 20 ft for 1 round as a swift action 3 times per day, though a DC 16 Will save (pretty easy for most things to beat by the time you'd have the money for this) reduces that to shaken. Still, getting a guaranteed shaken status on everyone within 20 ft with just a swift action isn't too shabby, and if you follow that up with an Intimidate check using the Never Outnumbered skill trick you can escalate that to frightened status, sending whole crowds running. The MIC also has an armor enhancement called Menacing, but I'm not so sure it's really worth it. On the one hand, it has a more significant effect (panics for 5 rounds instead of 1, though a successful save still reduces it to 1 round of being shaken) and is more difficult to resist (the Will save DC is calculated from your HD and Cha bonus, so it will definitely be higher and it scales with level), but it costs twice as much as Fearsome, using it takes a standard action rather than a swift action, and it only affects a single target, which must have fewer HD than you.
You mightalso be able to convince your DM to let you add an Intimidate-boosting enhancement to your armor using the rules for custom magic items, but that's kind of a gray area rules-wise, even moreso than the "masterwork tool" thing. If your DM does allow it, though, this would be a very easy and inexpensive way to boost your Intimidate modifier -- getting a +5 competence bonus to Intimidate from enchanting your armor would cost only 3750 gp (I'm assuming this will require the 1.5x price modifier for using a nonstandard body slot), and you could get it up to +10 for the same price as that Fearsome enhancement mentioned above.
But as far as just getting your armor to match the description you gave, the bare minimum you really need is a set of standard full plate with armor spikes, plus the cost of a masterwork tool if you want it to contribute to your Intimidate checks. The game rules generally don't care so much about strictly descriptive details, only the impact things have mechanically.
