HTPC Build (Please Help)

Hi,


I am interested in building an HTPC from an existing PC and need help with the hardware configuration.

I would like to have a dual OTA tuner (with the ability to record and watch HDTV at the same time), record and watch OTA and satellite, be able to access the HTPC throughout the house via remote control to 2 tv's and 1 home theater projector.

I have cabling to all the TV's and projector coming to a central location in the in house.


Purchase Date: ASAP

I don't have any preference in regards to where or what type of parts or OS I would get and the budget is = to the best performance that I can get while keeping costs down. Laggy playback and delays would be unacceptable. Essentially, I would like the system to be like a PVR for OTA and satellite for the whole house (not much to ask, lol).

The current config is:

Operating System
Windows XP Professional x64 Edition Service Pack 2

Processor
3.00 gigahertz Intel Pentium D
16 kilobyte primary memory cache
1024 kilobyte secondary memory cache

Board: ASUSTeK Computer INC. P5LD2 Rev 1.xx
Bus Clock: 200 megahertz

Drives:
250.99 Gigabytes Usable Hard Drive Capacity
69.03 Gigabytes Hard Drive Free Space

HL-DT-ST DVD-ROM GDR8163B [CD-ROM drive]
HP DVD Writer 740b [CD-ROM drive]
LITE-ON DVDRW LH-20A1H USB Device [CD-ROM drive]
3.5" format removeable media [Floppy drive]

Maxtor 6L250S0 [Hard drive] (250.99 GB) -- drive 0

3072 Megabytes Installed Memory

NVIDIA GeForce 7800 GT [Display adapter]

Creative SB Audigy 2 ZS (WDM)


1394 Net Adapter
Marvell Yukon 88E8053 PCI-E Gigabit Ethernet Controller

Antec Design Case

Enermax Noisetaker 485w PSU

Your help would be very much appreciated.

Many thanks in advance !!!