I've been tasked with adding a blog to an already up and running client site. The site uses wordpress as it's CMS already. So a blog install should be a relatively simply task and simply a matter of blending in the stylings of the blog to match the clients taste. However I get the sinking feeling that the client has already set up a "blog" with there testimonials page. I've not yet got the access passwords from the client to look under the hood but I thought I'd get an early start on my workload and do some research into my options. Theoretically I'm going to have to find a way to create another blog section within the site. I've come up with four options and I wanted the opinion of the wordpress community as to which one would be best. One of the key factors to bare in mind is that I would prefer to leave installing a second wordpress cms as that will end up causing confusion for the client, however I'm open to arguments if it turns out to be what the community think is best practice.
So far my options as I see them are:
A second install of wordpress in a sub folder and then link through from the clients original site. This has all sorts of draw backs though as I'll be duplicating login credentials, having to replicate the theme, two sets of plugins to upgrade and maintain and may well be detrimental to the sites SEO if I have to start setting up redirects or fixing broken links ect. Like I say though if there is a strong argument for a second install that I'm missing then I'm open to suggestions.
Wordpress network site. This came up in a quick google search, I've never set up one before and I was wondering if anyone could list some pro's or cons. I'm not entirely convinced this is the right way to go, but again, I'm not an expert so this could be what I'm after. From what I've read (which at this point is limited to the codex) this would allow me to set up a second site but from the same install. Would this allow me to maintain one set of plug=ins/login details/theme but run two Blogs? Any idea what the affect on SEO mite be?
Using a plug in. This seems like the sound option and I've already earmarked a plug in that could do the job. However I'm worried about the long term support and don't want to be getting a frantic email from a client because the plug in is no longer supported in a future wordpress update. However the pro's (from what I've read) are that I can generate a template page and seperate the posts via the categories. Once the site is live I'll be managing the blog entries anyway so this would be beneficial. Also as the new blog will be built by inserting a series of codes into a template I shouldn't have to do too much in the way of styling as the css and layout from the theme should still apply (in theory :) .
Any hoo, So far it looks like option three is the main contender, but I thought I'd throw it open to the forums to see if there are any reasons that options 1 or 2 would be better, or a possible option 4 that I'd not considered.
Thanks in advance for any help guys.