My Perfect Twitter Client Please

Twitter is running on my PC all day (and on the iPhone when I’m away) and I dip in and out constantly but my head is wrecked trying to find a Twitter app that has all I need. Lots come close but all let me down in one crucial area. I’ve tried the following:

• Website – No alerts. Feature light.
• Hootsuite – No notifications for replies, dm’s only. Slightly slow as it runs in a browser. No visual marking of read/unread tweets. No sync with iPhone.
• Twhirl – Buggy. Keeps showing tweets as unread on startup. No Reply all. No iPhone app.
• Echofon – Almost featureless Firefox plugin.
• Tweetdeck – Too large a footprint on the PC and hard to read.
• Twitteriffic – No PC client.
• Tweetie – No PC client.
• Seesmic – No iPhone client. No Multiple accounts. No lasting highlighting of unread tweets.
• TwitBird – No PC client.

Here’s a list of specs I’d like to see:

• NB Proper syncing between Desktop and iPhone versions of the same client. I really need stuff I’ve already read on the PC to be marked read on the iPhone app and vice versa.
• Ease of use and visually minimalist.
• Fast.
• Highlight unread and Reply tweets.
• Scroll to first unread tweet.
• Control over notifications, ie – audio & visual push alerts.
• Preview Short url’s.
• Multiple accounts.
• Select account to tweet from on each new tweet.
• Show quick profile, stats and follow/unfollow links.
• Quick links to Reply, DM users.
• Favorite following.
• Auto shortlinking.
• Tweet audio, video and photos.
• Tweet and link stats.
• Text compression.
• Sync with Outlook address book.
• Filtering – see replies, dm’s only.
• Auto suggest Twitter handles and Hashtags when composing.
• Advanced search for tweets and Profiles.
• Geotagging.
• Send to Facebook, Linked, etc..on each new tweet.
• Schedule tweets.
• iPhone Autosave on exit.
• Conversation Threads

Please correct anything I may have got wrong above or point me to my ideal Twitter client!

Leon.