Sportdog, as mentioned above, you are starting with a good solid platform. I've seen several modern Vanguards shoot 1/2" groups out of the box with good factory ammo, such as the Nosler Custom. The SWFA's Tanner mentioned are a good value, or if funds are plentiful you could step up to a Leupold Mk4 LR/T. The 4.5-14x is a good, multi-purpose magnification range for a LR rig. As for the trigger, if you want to upgrade to a Timney it takes about 2 screws and 2 minutes and to swap it out.
As for load development, here's the basic order.
Always start with the longer OAL you may use. In this case that would be just off the lands, or at magazine length, which ever is longer.
Now not all bullets and powder like each other, so I usually pick one, or the other, and find the partner it likes. Since you do not seen to have a large supply of either, I'd start with the bullet, and find the powder to match.
I assume you plan to hunt with this rifle, so for bullets, this is where I would start:
http://www.shootersproshop.com/nosl...nd-long-range-7mm-168gr-blems-100ct.htmlAs for Powders, all Tanner mentioned have great potential for your purpose. Start with any of those you have on the shelf. Start low, and work up. Whether you choose to use traditional groups or the ladder method is a matter of taste, and up to you. When you find a powder you bullets like, then you can buy a bunch of it.
Part of you method of load work up will depend on the availability of resources, such as how many powders you have on your shelf, and distance to the range. If it's close or just about the back door, load up a 3-5 at minimum with each usable powder you have on the shelf an d give each a try. Take which ever produces the best group and work up with that powder.
When you come to the primary load development stage, the rule is work up, then work in. Work up with your powder charge until you find your node, or max pressure, then work in with your over all length (OAL). Decreasing your OAL reduced your overall pressure (yes there are competing forces when reducing OAL but the net effect is a reduced OAL reduces pressure). I typically reduce OAL in .05" increments. Keep in mind it's nowt alway necessary to monkey with OAL. Reducing OAL is typically most effective when your groups are showing 2 in, and one out, or you are splitting groups. Increasing OAL often helps when you have an even dispersion but needs to be pulled in. But since we are starting an our MAX OAL, if you are not splitting groups we leave OAL alone.
Now the above play book works well with TRADITIONALLY DESIGNED BULLETS. If you are load developing for mono's (especially Barnes), or VLD's (especially Bergers), you've stepped into the realm of the Finicky Princess Beauty Queens, in which case your new order is, Multiple powders, OAL, in .1", or even .2" increments, and and then work up to max pressure.