Why did you unghost the portal  pages? Just curious…….

There is a re-ghosting tool but someone else will need to give you the place to get it. In terms of making  the sites run faster, without any additional information, I would say you need more hardware. But this recommendation is a shot in the dark.

you do know that once you reghost pages  that your customizations will
go away?

The GhostHunter web part: http://www.bluedoglimited.com/Downloads/pages/Web%20Part%20Toolkit.aspx

There is a tool call Universal SharePoint Manager. This will re-ghost sites for you as well as give you a report on all the sites that are un-ghosted. You can goto http://www.idevfactory.com to find this product. There is a 30-day trial available for download from this site.

Can you please give the ideal hardware configuration for sharepoint  consists of users 300 to 600.

We just deployed a medium farm at my company of about 900. I would probably say this would be good for you as well.

just the classic web/database setup should do.

sql server
1) ibm x346 8gb memory, 6 hard disks in 3 arrays
web server
1) ibm x306 2gb memory 2 hard disks 1 array.

-i would baseline with this config and scale out as necessary. it
would be easy to go to a medium farm from this config, just buy 2
more pizzaboxes (x306).