Beer style overviews (and details on brewing them):
Terminology:
How to Brew. The terminology at the web site is accurate. When brewing with extract, ignore the web site and get the 4th edition of the book.
This is going to have an impact on most IBU estimates. At a 'boil' temperature of 200F (roughly 'boiling' at 2000 feet), there is a noticeable reduction in hop utilization (see
Ask the Experts: Brewing at High Altitude (link)). A full hard boil isn't needed; level 1 or 2 in
Boiling Wort Visual Reference (link) is sufficient.
Pliny clones
Russian River Pliny the Elder Clone (AHA link) includes an extract plus steeping grains recipe. FWIW, the recipe uses 5% sugar (but see also #26). Also, the recipe uses dry malt extract (DME), not liquid malt extract (LME).
Lazy Chart For Converting DME, LME, ... (link) can help with the conversion. A "back of the envelope" estimate for FG for the extract version suggests 14-ish (not 11-ish). Whether or not that matters will depend on how each of us tastes beer. For me, IPAs (and DIPAs) are better in the 10-ish range for FG.
If I were brewing this recipe, I would use 6 lb DME & 1 lb sugar (vs 6.5 lb DME an 0.5 lb sugar) - partially to lower the FG and partially to avoid open packages. Using LME, it looks like 8 lb LME is needed. Not sure what size containers you can get with LME, but there is a combination of LME containers, 1 lb DME packages, and sugar that would avoid measuring partial containers of LME.
As for style of extract, I would go with the lightest color of LME ("extra light" or "pilsen"). For best hop utilization you could do a full volume (5 gal, not 2.5 gal) boil. Half the LME at the start of the boil (and the rest towards the end of the boil) will also help with hop utilization. Recipe software will be useful when estimating IBUs.