The industry "standard" is the Nikon Coolscan 5000. This is the unit that everyone who has a lot of film to scan uses. They cost about $1k
http://www.nikonusa.com/Find-Your-Nikon/ProductDetail.page?pid=9238
But
be warned. This is a
HUGE job. Every slide needs to be cleaned at least with a blast of canned air, but some with a camel hair brush, scanned and then you absolutly have to put it into Photoshop and do some hand work or at least look and varify that none is required. If you can do one slide in five minutes you are working at a good speed. Don't expect that you can beat that pace. Many slides WILL need to have some dust and scratches removed using Photoshop. The scanner's automatic exposure and color balance is never perfect. Most take about 3 minutes of work to be passable and more to be perfect.
The scanner users Kodak "ICE" to remove dust and scratches. Whatever scanner y get make sure it has this. Kodak licenses ICE to all the scanner makers. It works well to remove 80% of the junk.
For about $2,000 you can hire this job out and be done with it or you can spend $1,000 for a scanner and 400 to 500 hours of your time.
One place that can do the work in scancafe.com They have good quality control. You can get the slides scanned at 3,000 DPI JPG for cheap or for about double the price you can have them scanned to 4,000 DPI TIFF files.
If these slides are very high quality (good equipment, technique and fine grain film) and you want to edit them then 4,000 dpi tiffs are best but if you just want to look at them JPG will do fine.
I'm working on a scanning project also and I've decided by time is worth more then $1 per hour so I've outsourced the scanning. But I still have to tag each image with meta data and load it into Aperture. You really can't get around this last part. If you don't tag each image then 8,000 image files with names like IMG03245.TIF will just be useless to you. I have been sending between 1,000 and 1,500 images out each month because that is all the time I have for entering the metadata tags