What type of riding?
One thing that has not been addressed yet is you have to think about what kind of riding you will be doing: dirt or street? I have 2 different sets of gear depending on what the majority of my day looks like. I have the luxury of not having to ride many pavement miles at all to get to the dirt though.
Since you are on a Tiger I am going to assume you will be doing more street miles along with some basic forest service and dirt roads. I would lean more towards the street side of things. You will find very few products actually made for 'dual sport riders' although that is changing in my opinion.
I prefer a dirt helmet almost all the time b/c it is lighter and better ventilated. I used a Scorpion for a few years which is a great value at $150 for the higher end one. I recently gave in and bought an Arai XD so I could have a face shield (like a street helmet) during these cold winter months coming up. I am happy with it so far, and managed to find one new far less than the $500 MSRP. Someone earlier said that a more expensive helmet will fit better and that is not true. Find one that fits your head, that is the most important thing. A more $ lid brings more features usually, and the finish is usually better. If Scorpion made a dual sport helmet like the XD I would sell the XD in a SECOND.
I am always trying to find the 'prefect' jacket and still have not found it, although yesterday I did end up buying a Tourmaster Transition 2 and believe it is worth every bit of the $160 I paid for it. Dirty South has crash tested one and it held up good enough to keep wearing. Apparently it is waterproof from the outside, not due to a liner (waterproof liners mean all the outside of the coat gets soaked). Also has a great amount of vents. I think this could be 'the one!' Also, I am a fan of the harder armor, not the soft stuff that First Gear and some others use.
Pants, again, find something that vents and can get you home dry should the weather turn foul. I have some Hein Gericke Toureg pants I like on the street, although you cannot buy them in the states. They do have knee and hip armor and are waterproof, but they do not vent at all and get too hot in the summer.
Gloves- get some that are not too bulky so you can feel the grips. Even in winter I wear thin gloves...along with heated grips you cannot go wrong. I just bought some Alpinestars that were like $40 and seem good for the $. I keep a pair of MX gloves in my pockets at all times in case it gets hot or my original get too wet.
Boots- I second the Sidi Discoveries. They have been waterproof so far and seem to be wearing good. They are one of the few products made for dualsporters. Alot of guys like the Gaerne Explorers but I hear they leak like a sieve. The Discos run about $250 and the Expl about $150. In my opinion your hiking boots are not good enough. For one thing, your laces could come untied and get in your chain, etc.
What else? Dirty got me into wearing earplugs and like him I cannot ride without them anymore. It makes stopping at lights to talk to your buddies a very public conversation but at least I won't be deaf when I'm old. A fleece balaclava can help keep your neck and upper chest warm on chilly days. I have one from Schampa and love it.